My image renders in black and white and not on the color it shows on the compositor?
What you see in the backdrop of the compositor is the output plugged to the active "Viewer" node in compositor, while the final render result is the thing that is plugged into the "Composite" node. From your screenshot it looks like your "Composite" node is not plugged into the end of the node chain, but rather into some node a bit earlier in the chain. Attach it into the same socket your viewer node is plugged into, and you should get the same result you see.